Files
clang-p2996/clang/lib/Format/WhitespaceManager.cpp
Sam McCall 04ee232ff2 clang-format: Add new style option AlignConsecutiveMacros
This option behaves similarly to AlignConsecutiveDeclarations and
AlignConsecutiveAssignments, aligning the assignment of C/C++
preprocessor macros on consecutive lines.

I've worked in many projects (embedded, mostly) where header files full
of large, well-aligned "#define" blocks are a common pattern. We
normally avoid using clang-format on these files, since it ruins any
existing alignment in said blocks. This style option will align "simple"
PP macros (no parameters) and PP macros with parameter lists on
consecutive lines.

Related Bugzilla entry (thanks mcuddie):
https://llvm.org/bugs/show_bug.cgi?id=20637

Patch by Nick Renieris (VelocityRa)!

Differential Revision: https://reviews.llvm.org/D28462

llvm-svn: 364938
2019-07-02 15:53:14 +00:00

859 lines
33 KiB
C++

//===--- WhitespaceManager.cpp - Format C++ code --------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements WhitespaceManager class.
///
//===----------------------------------------------------------------------===//
#include "WhitespaceManager.h"
#include "llvm/ADT/STLExtras.h"
namespace clang {
namespace format {
bool WhitespaceManager::Change::IsBeforeInFile::
operator()(const Change &C1, const Change &C2) const {
return SourceMgr.isBeforeInTranslationUnit(
C1.OriginalWhitespaceRange.getBegin(),
C2.OriginalWhitespaceRange.getBegin());
}
WhitespaceManager::Change::Change(const FormatToken &Tok,
bool CreateReplacement,
SourceRange OriginalWhitespaceRange,
int Spaces, unsigned StartOfTokenColumn,
unsigned NewlinesBefore,
StringRef PreviousLinePostfix,
StringRef CurrentLinePrefix,
bool ContinuesPPDirective, bool IsInsideToken)
: Tok(&Tok), CreateReplacement(CreateReplacement),
OriginalWhitespaceRange(OriginalWhitespaceRange),
StartOfTokenColumn(StartOfTokenColumn), NewlinesBefore(NewlinesBefore),
PreviousLinePostfix(PreviousLinePostfix),
CurrentLinePrefix(CurrentLinePrefix),
ContinuesPPDirective(ContinuesPPDirective), Spaces(Spaces),
IsInsideToken(IsInsideToken), IsTrailingComment(false), TokenLength(0),
PreviousEndOfTokenColumn(0), EscapedNewlineColumn(0),
StartOfBlockComment(nullptr), IndentationOffset(0) {}
void WhitespaceManager::replaceWhitespace(FormatToken &Tok, unsigned Newlines,
unsigned Spaces,
unsigned StartOfTokenColumn,
bool InPPDirective) {
if (Tok.Finalized)
return;
Tok.Decision = (Newlines > 0) ? FD_Break : FD_Continue;
Changes.push_back(Change(Tok, /*CreateReplacement=*/true, Tok.WhitespaceRange,
Spaces, StartOfTokenColumn, Newlines, "", "",
InPPDirective && !Tok.IsFirst,
/*IsInsideToken=*/false));
}
void WhitespaceManager::addUntouchableToken(const FormatToken &Tok,
bool InPPDirective) {
if (Tok.Finalized)
return;
Changes.push_back(Change(Tok, /*CreateReplacement=*/false,
Tok.WhitespaceRange, /*Spaces=*/0,
Tok.OriginalColumn, Tok.NewlinesBefore, "", "",
InPPDirective && !Tok.IsFirst,
/*IsInsideToken=*/false));
}
llvm::Error
WhitespaceManager::addReplacement(const tooling::Replacement &Replacement) {
return Replaces.add(Replacement);
}
void WhitespaceManager::replaceWhitespaceInToken(
const FormatToken &Tok, unsigned Offset, unsigned ReplaceChars,
StringRef PreviousPostfix, StringRef CurrentPrefix, bool InPPDirective,
unsigned Newlines, int Spaces) {
if (Tok.Finalized)
return;
SourceLocation Start = Tok.getStartOfNonWhitespace().getLocWithOffset(Offset);
Changes.push_back(
Change(Tok, /*CreateReplacement=*/true,
SourceRange(Start, Start.getLocWithOffset(ReplaceChars)), Spaces,
std::max(0, Spaces), Newlines, PreviousPostfix, CurrentPrefix,
InPPDirective && !Tok.IsFirst, /*IsInsideToken=*/true));
}
const tooling::Replacements &WhitespaceManager::generateReplacements() {
if (Changes.empty())
return Replaces;
llvm::sort(Changes, Change::IsBeforeInFile(SourceMgr));
calculateLineBreakInformation();
alignConsecutiveMacros();
alignConsecutiveDeclarations();
alignConsecutiveAssignments();
alignTrailingComments();
alignEscapedNewlines();
generateChanges();
return Replaces;
}
void WhitespaceManager::calculateLineBreakInformation() {
Changes[0].PreviousEndOfTokenColumn = 0;
Change *LastOutsideTokenChange = &Changes[0];
for (unsigned i = 1, e = Changes.size(); i != e; ++i) {
SourceLocation OriginalWhitespaceStart =
Changes[i].OriginalWhitespaceRange.getBegin();
SourceLocation PreviousOriginalWhitespaceEnd =
Changes[i - 1].OriginalWhitespaceRange.getEnd();
unsigned OriginalWhitespaceStartOffset =
SourceMgr.getFileOffset(OriginalWhitespaceStart);
unsigned PreviousOriginalWhitespaceEndOffset =
SourceMgr.getFileOffset(PreviousOriginalWhitespaceEnd);
assert(PreviousOriginalWhitespaceEndOffset <=
OriginalWhitespaceStartOffset);
const char *const PreviousOriginalWhitespaceEndData =
SourceMgr.getCharacterData(PreviousOriginalWhitespaceEnd);
StringRef Text(PreviousOriginalWhitespaceEndData,
SourceMgr.getCharacterData(OriginalWhitespaceStart) -
PreviousOriginalWhitespaceEndData);
// Usually consecutive changes would occur in consecutive tokens. This is
// not the case however when analyzing some preprocessor runs of the
// annotated lines. For example, in this code:
//
// #if A // line 1
// int i = 1;
// #else B // line 2
// int i = 2;
// #endif // line 3
//
// one of the runs will produce the sequence of lines marked with line 1, 2
// and 3. So the two consecutive whitespace changes just before '// line 2'
// and before '#endif // line 3' span multiple lines and tokens:
//
// #else B{change X}[// line 2
// int i = 2;
// ]{change Y}#endif // line 3
//
// For this reason, if the text between consecutive changes spans multiple
// newlines, the token length must be adjusted to the end of the original
// line of the token.
auto NewlinePos = Text.find_first_of('\n');
if (NewlinePos == StringRef::npos) {
Changes[i - 1].TokenLength = OriginalWhitespaceStartOffset -
PreviousOriginalWhitespaceEndOffset +
Changes[i].PreviousLinePostfix.size() +
Changes[i - 1].CurrentLinePrefix.size();
} else {
Changes[i - 1].TokenLength =
NewlinePos + Changes[i - 1].CurrentLinePrefix.size();
}
// If there are multiple changes in this token, sum up all the changes until
// the end of the line.
if (Changes[i - 1].IsInsideToken && Changes[i - 1].NewlinesBefore == 0)
LastOutsideTokenChange->TokenLength +=
Changes[i - 1].TokenLength + Changes[i - 1].Spaces;
else
LastOutsideTokenChange = &Changes[i - 1];
Changes[i].PreviousEndOfTokenColumn =
Changes[i - 1].StartOfTokenColumn + Changes[i - 1].TokenLength;
Changes[i - 1].IsTrailingComment =
(Changes[i].NewlinesBefore > 0 || Changes[i].Tok->is(tok::eof) ||
(Changes[i].IsInsideToken && Changes[i].Tok->is(tok::comment))) &&
Changes[i - 1].Tok->is(tok::comment) &&
// FIXME: This is a dirty hack. The problem is that
// BreakableLineCommentSection does comment reflow changes and here is
// the aligning of trailing comments. Consider the case where we reflow
// the second line up in this example:
//
// // line 1
// // line 2
//
// That amounts to 2 changes by BreakableLineCommentSection:
// - the first, delimited by (), for the whitespace between the tokens,
// - and second, delimited by [], for the whitespace at the beginning
// of the second token:
//
// // line 1(
// )[// ]line 2
//
// So in the end we have two changes like this:
//
// // line1()[ ]line 2
//
// Note that the OriginalWhitespaceStart of the second change is the
// same as the PreviousOriginalWhitespaceEnd of the first change.
// In this case, the below check ensures that the second change doesn't
// get treated as a trailing comment change here, since this might
// trigger additional whitespace to be wrongly inserted before "line 2"
// by the comment aligner here.
//
// For a proper solution we need a mechanism to say to WhitespaceManager
// that a particular change breaks the current sequence of trailing
// comments.
OriginalWhitespaceStart != PreviousOriginalWhitespaceEnd;
}
// FIXME: The last token is currently not always an eof token; in those
// cases, setting TokenLength of the last token to 0 is wrong.
Changes.back().TokenLength = 0;
Changes.back().IsTrailingComment = Changes.back().Tok->is(tok::comment);
const WhitespaceManager::Change *LastBlockComment = nullptr;
for (auto &Change : Changes) {
// Reset the IsTrailingComment flag for changes inside of trailing comments
// so they don't get realigned later. Comment line breaks however still need
// to be aligned.
if (Change.IsInsideToken && Change.NewlinesBefore == 0)
Change.IsTrailingComment = false;
Change.StartOfBlockComment = nullptr;
Change.IndentationOffset = 0;
if (Change.Tok->is(tok::comment)) {
if (Change.Tok->is(TT_LineComment) || !Change.IsInsideToken)
LastBlockComment = &Change;
else {
if ((Change.StartOfBlockComment = LastBlockComment))
Change.IndentationOffset =
Change.StartOfTokenColumn -
Change.StartOfBlockComment->StartOfTokenColumn;
}
} else {
LastBlockComment = nullptr;
}
}
}
// Align a single sequence of tokens, see AlignTokens below.
template <typename F>
static void
AlignTokenSequence(unsigned Start, unsigned End, unsigned Column, F &&Matches,
SmallVector<WhitespaceManager::Change, 16> &Changes) {
bool FoundMatchOnLine = false;
int Shift = 0;
// ScopeStack keeps track of the current scope depth. It contains indices of
// the first token on each scope.
// We only run the "Matches" function on tokens from the outer-most scope.
// However, we do need to pay special attention to one class of tokens
// that are not in the outer-most scope, and that is function parameters
// which are split across multiple lines, as illustrated by this example:
// double a(int x);
// int b(int y,
// double z);
// In the above example, we need to take special care to ensure that
// 'double z' is indented along with it's owning function 'b'.
SmallVector<unsigned, 16> ScopeStack;
for (unsigned i = Start; i != End; ++i) {
if (ScopeStack.size() != 0 &&
Changes[i].indentAndNestingLevel() <
Changes[ScopeStack.back()].indentAndNestingLevel())
ScopeStack.pop_back();
// Compare current token to previous non-comment token to ensure whether
// it is in a deeper scope or not.
unsigned PreviousNonComment = i - 1;
while (PreviousNonComment > Start &&
Changes[PreviousNonComment].Tok->is(tok::comment))
PreviousNonComment--;
if (i != Start && Changes[i].indentAndNestingLevel() >
Changes[PreviousNonComment].indentAndNestingLevel())
ScopeStack.push_back(i);
bool InsideNestedScope = ScopeStack.size() != 0;
if (Changes[i].NewlinesBefore > 0 && !InsideNestedScope) {
Shift = 0;
FoundMatchOnLine = false;
}
// If this is the first matching token to be aligned, remember by how many
// spaces it has to be shifted, so the rest of the changes on the line are
// shifted by the same amount
if (!FoundMatchOnLine && !InsideNestedScope && Matches(Changes[i])) {
FoundMatchOnLine = true;
Shift = Column - Changes[i].StartOfTokenColumn;
Changes[i].Spaces += Shift;
}
// This is for function parameters that are split across multiple lines,
// as mentioned in the ScopeStack comment.
if (InsideNestedScope && Changes[i].NewlinesBefore > 0) {
unsigned ScopeStart = ScopeStack.back();
if (Changes[ScopeStart - 1].Tok->is(TT_FunctionDeclarationName) ||
(ScopeStart > Start + 1 &&
Changes[ScopeStart - 2].Tok->is(TT_FunctionDeclarationName)))
Changes[i].Spaces += Shift;
}
assert(Shift >= 0);
Changes[i].StartOfTokenColumn += Shift;
if (i + 1 != Changes.size())
Changes[i + 1].PreviousEndOfTokenColumn += Shift;
}
}
// Walk through a subset of the changes, starting at StartAt, and find
// sequences of matching tokens to align. To do so, keep track of the lines and
// whether or not a matching token was found on a line. If a matching token is
// found, extend the current sequence. If the current line cannot be part of a
// sequence, e.g. because there is an empty line before it or it contains only
// non-matching tokens, finalize the previous sequence.
// The value returned is the token on which we stopped, either because we
// exhausted all items inside Changes, or because we hit a scope level higher
// than our initial scope.
// This function is recursive. Each invocation processes only the scope level
// equal to the initial level, which is the level of Changes[StartAt].
// If we encounter a scope level greater than the initial level, then we call
// ourselves recursively, thereby avoiding the pollution of the current state
// with the alignment requirements of the nested sub-level. This recursive
// behavior is necessary for aligning function prototypes that have one or more
// arguments.
// If this function encounters a scope level less than the initial level,
// it returns the current position.
// There is a non-obvious subtlety in the recursive behavior: Even though we
// defer processing of nested levels to recursive invocations of this
// function, when it comes time to align a sequence of tokens, we run the
// alignment on the entire sequence, including the nested levels.
// When doing so, most of the nested tokens are skipped, because their
// alignment was already handled by the recursive invocations of this function.
// However, the special exception is that we do NOT skip function parameters
// that are split across multiple lines. See the test case in FormatTest.cpp
// that mentions "split function parameter alignment" for an example of this.
template <typename F>
static unsigned AlignTokens(const FormatStyle &Style, F &&Matches,
SmallVector<WhitespaceManager::Change, 16> &Changes,
unsigned StartAt) {
unsigned MinColumn = 0;
unsigned MaxColumn = UINT_MAX;
// Line number of the start and the end of the current token sequence.
unsigned StartOfSequence = 0;
unsigned EndOfSequence = 0;
// Measure the scope level (i.e. depth of (), [], {}) of the first token, and
// abort when we hit any token in a higher scope than the starting one.
auto IndentAndNestingLevel = StartAt < Changes.size()
? Changes[StartAt].indentAndNestingLevel()
: std::pair<unsigned, unsigned>(0, 0);
// Keep track of the number of commas before the matching tokens, we will only
// align a sequence of matching tokens if they are preceded by the same number
// of commas.
unsigned CommasBeforeLastMatch = 0;
unsigned CommasBeforeMatch = 0;
// Whether a matching token has been found on the current line.
bool FoundMatchOnLine = false;
// Aligns a sequence of matching tokens, on the MinColumn column.
//
// Sequences start from the first matching token to align, and end at the
// first token of the first line that doesn't need to be aligned.
//
// We need to adjust the StartOfTokenColumn of each Change that is on a line
// containing any matching token to be aligned and located after such token.
auto AlignCurrentSequence = [&] {
if (StartOfSequence > 0 && StartOfSequence < EndOfSequence)
AlignTokenSequence(StartOfSequence, EndOfSequence, MinColumn, Matches,
Changes);
MinColumn = 0;
MaxColumn = UINT_MAX;
StartOfSequence = 0;
EndOfSequence = 0;
};
unsigned i = StartAt;
for (unsigned e = Changes.size(); i != e; ++i) {
if (Changes[i].indentAndNestingLevel() < IndentAndNestingLevel)
break;
if (Changes[i].NewlinesBefore != 0) {
CommasBeforeMatch = 0;
EndOfSequence = i;
// If there is a blank line, or if the last line didn't contain any
// matching token, the sequence ends here.
if (Changes[i].NewlinesBefore > 1 || !FoundMatchOnLine)
AlignCurrentSequence();
FoundMatchOnLine = false;
}
if (Changes[i].Tok->is(tok::comma)) {
++CommasBeforeMatch;
} else if (Changes[i].indentAndNestingLevel() > IndentAndNestingLevel) {
// Call AlignTokens recursively, skipping over this scope block.
unsigned StoppedAt = AlignTokens(Style, Matches, Changes, i);
i = StoppedAt - 1;
continue;
}
if (!Matches(Changes[i]))
continue;
// If there is more than one matching token per line, or if the number of
// preceding commas, do not match anymore, end the sequence.
if (FoundMatchOnLine || CommasBeforeMatch != CommasBeforeLastMatch)
AlignCurrentSequence();
CommasBeforeLastMatch = CommasBeforeMatch;
FoundMatchOnLine = true;
if (StartOfSequence == 0)
StartOfSequence = i;
unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
int LineLengthAfter = -Changes[i].Spaces;
for (unsigned j = i; j != e && Changes[j].NewlinesBefore == 0; ++j)
LineLengthAfter += Changes[j].Spaces + Changes[j].TokenLength;
unsigned ChangeMaxColumn = Style.ColumnLimit - LineLengthAfter;
// If we are restricted by the maximum column width, end the sequence.
if (ChangeMinColumn > MaxColumn || ChangeMaxColumn < MinColumn ||
CommasBeforeLastMatch != CommasBeforeMatch) {
AlignCurrentSequence();
StartOfSequence = i;
}
MinColumn = std::max(MinColumn, ChangeMinColumn);
MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
}
EndOfSequence = i;
AlignCurrentSequence();
return i;
}
// Aligns a sequence of matching tokens, on the MinColumn column.
//
// Sequences start from the first matching token to align, and end at the
// first token of the first line that doesn't need to be aligned.
//
// We need to adjust the StartOfTokenColumn of each Change that is on a line
// containing any matching token to be aligned and located after such token.
static void AlignMacroSequence(
unsigned &StartOfSequence, unsigned &EndOfSequence, unsigned &MinColumn,
unsigned &MaxColumn, bool &FoundMatchOnLine,
std::function<bool(const WhitespaceManager::Change &C)> AlignMacrosMatches,
SmallVector<WhitespaceManager::Change, 16> &Changes) {
if (StartOfSequence > 0 && StartOfSequence < EndOfSequence) {
FoundMatchOnLine = false;
int Shift = 0;
for (unsigned I = StartOfSequence; I != EndOfSequence; ++I) {
if (Changes[I].NewlinesBefore > 0) {
Shift = 0;
FoundMatchOnLine = false;
}
// If this is the first matching token to be aligned, remember by how many
// spaces it has to be shifted, so the rest of the changes on the line are
// shifted by the same amount
if (!FoundMatchOnLine && AlignMacrosMatches(Changes[I])) {
FoundMatchOnLine = true;
Shift = MinColumn - Changes[I].StartOfTokenColumn;
Changes[I].Spaces += Shift;
}
assert(Shift >= 0);
Changes[I].StartOfTokenColumn += Shift;
if (I + 1 != Changes.size())
Changes[I + 1].PreviousEndOfTokenColumn += Shift;
}
}
MinColumn = 0;
MaxColumn = UINT_MAX;
StartOfSequence = 0;
EndOfSequence = 0;
}
void WhitespaceManager::alignConsecutiveMacros() {
if (!Style.AlignConsecutiveMacros)
return;
auto AlignMacrosMatches = [](const Change &C) {
const FormatToken *Current = C.Tok;
unsigned SpacesRequiredBefore = 1;
if (Current->SpacesRequiredBefore == 0 || !Current->Previous)
return false;
Current = Current->Previous;
// If token is a ")", skip over the parameter list, to the
// token that precedes the "("
if (Current->is(tok::r_paren) && Current->MatchingParen) {
Current = Current->MatchingParen->Previous;
SpacesRequiredBefore = 0;
}
if (!Current || !Current->is(tok::identifier))
return false;
if (!Current->Previous || !Current->Previous->is(tok::pp_define))
return false;
// For a macro function, 0 spaces are required between the
// identifier and the lparen that opens the parameter list.
// For a simple macro, 1 space is required between the
// identifier and the first token of the defined value.
return Current->Next->SpacesRequiredBefore == SpacesRequiredBefore;
};
unsigned MinColumn = 0;
unsigned MaxColumn = UINT_MAX;
// Start and end of the token sequence we're processing.
unsigned StartOfSequence = 0;
unsigned EndOfSequence = 0;
// Whether a matching token has been found on the current line.
bool FoundMatchOnLine = false;
unsigned I = 0;
for (unsigned E = Changes.size(); I != E; ++I) {
if (Changes[I].NewlinesBefore != 0) {
EndOfSequence = I;
// If there is a blank line, or if the last line didn't contain any
// matching token, the sequence ends here.
if (Changes[I].NewlinesBefore > 1 || !FoundMatchOnLine)
AlignMacroSequence(StartOfSequence, EndOfSequence, MinColumn, MaxColumn,
FoundMatchOnLine, AlignMacrosMatches, Changes);
FoundMatchOnLine = false;
}
if (!AlignMacrosMatches(Changes[I]))
continue;
FoundMatchOnLine = true;
if (StartOfSequence == 0)
StartOfSequence = I;
unsigned ChangeMinColumn = Changes[I].StartOfTokenColumn;
int LineLengthAfter = -Changes[I].Spaces;
for (unsigned j = I; j != E && Changes[j].NewlinesBefore == 0; ++j)
LineLengthAfter += Changes[j].Spaces + Changes[j].TokenLength;
unsigned ChangeMaxColumn = Style.ColumnLimit - LineLengthAfter;
MinColumn = std::max(MinColumn, ChangeMinColumn);
MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
}
EndOfSequence = I;
AlignMacroSequence(StartOfSequence, EndOfSequence, MinColumn, MaxColumn,
FoundMatchOnLine, AlignMacrosMatches, Changes);
}
void WhitespaceManager::alignConsecutiveAssignments() {
if (!Style.AlignConsecutiveAssignments)
return;
AlignTokens(
Style,
[&](const Change &C) {
// Do not align on equal signs that are first on a line.
if (C.NewlinesBefore > 0)
return false;
// Do not align on equal signs that are last on a line.
if (&C != &Changes.back() && (&C + 1)->NewlinesBefore > 0)
return false;
return C.Tok->is(tok::equal);
},
Changes, /*StartAt=*/0);
}
void WhitespaceManager::alignConsecutiveDeclarations() {
if (!Style.AlignConsecutiveDeclarations)
return;
// FIXME: Currently we don't handle properly the PointerAlignment: Right
// The * and & are not aligned and are left dangling. Something has to be done
// about it, but it raises the question of alignment of code like:
// const char* const* v1;
// float const* v2;
// SomeVeryLongType const& v3;
AlignTokens(
Style,
[](Change const &C) {
// tok::kw_operator is necessary for aligning operator overload
// definitions.
if (C.Tok->isOneOf(TT_FunctionDeclarationName, tok::kw_operator))
return true;
if (C.Tok->isNot(TT_StartOfName))
return false;
// Check if there is a subsequent name that starts the same declaration.
for (FormatToken *Next = C.Tok->Next; Next; Next = Next->Next) {
if (Next->is(tok::comment))
continue;
if (!Next->Tok.getIdentifierInfo())
break;
if (Next->isOneOf(TT_StartOfName, TT_FunctionDeclarationName,
tok::kw_operator))
return false;
}
return true;
},
Changes, /*StartAt=*/0);
}
void WhitespaceManager::alignTrailingComments() {
unsigned MinColumn = 0;
unsigned MaxColumn = UINT_MAX;
unsigned StartOfSequence = 0;
bool BreakBeforeNext = false;
unsigned Newlines = 0;
for (unsigned i = 0, e = Changes.size(); i != e; ++i) {
if (Changes[i].StartOfBlockComment)
continue;
Newlines += Changes[i].NewlinesBefore;
if (!Changes[i].IsTrailingComment)
continue;
unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
unsigned ChangeMaxColumn;
if (Style.ColumnLimit == 0)
ChangeMaxColumn = UINT_MAX;
else if (Style.ColumnLimit >= Changes[i].TokenLength)
ChangeMaxColumn = Style.ColumnLimit - Changes[i].TokenLength;
else
ChangeMaxColumn = ChangeMinColumn;
// If we don't create a replacement for this change, we have to consider
// it to be immovable.
if (!Changes[i].CreateReplacement)
ChangeMaxColumn = ChangeMinColumn;
if (i + 1 != e && Changes[i + 1].ContinuesPPDirective)
ChangeMaxColumn -= 2;
// If this comment follows an } in column 0, it probably documents the
// closing of a namespace and we don't want to align it.
bool FollowsRBraceInColumn0 = i > 0 && Changes[i].NewlinesBefore == 0 &&
Changes[i - 1].Tok->is(tok::r_brace) &&
Changes[i - 1].StartOfTokenColumn == 0;
bool WasAlignedWithStartOfNextLine = false;
if (Changes[i].NewlinesBefore == 1) { // A comment on its own line.
unsigned CommentColumn = SourceMgr.getSpellingColumnNumber(
Changes[i].OriginalWhitespaceRange.getEnd());
for (unsigned j = i + 1; j != e; ++j) {
if (Changes[j].Tok->is(tok::comment))
continue;
unsigned NextColumn = SourceMgr.getSpellingColumnNumber(
Changes[j].OriginalWhitespaceRange.getEnd());
// The start of the next token was previously aligned with the
// start of this comment.
WasAlignedWithStartOfNextLine =
CommentColumn == NextColumn ||
CommentColumn == NextColumn + Style.IndentWidth;
break;
}
}
if (!Style.AlignTrailingComments || FollowsRBraceInColumn0) {
alignTrailingComments(StartOfSequence, i, MinColumn);
MinColumn = ChangeMinColumn;
MaxColumn = ChangeMinColumn;
StartOfSequence = i;
} else if (BreakBeforeNext || Newlines > 1 ||
(ChangeMinColumn > MaxColumn || ChangeMaxColumn < MinColumn) ||
// Break the comment sequence if the previous line did not end
// in a trailing comment.
(Changes[i].NewlinesBefore == 1 && i > 0 &&
!Changes[i - 1].IsTrailingComment) ||
WasAlignedWithStartOfNextLine) {
alignTrailingComments(StartOfSequence, i, MinColumn);
MinColumn = ChangeMinColumn;
MaxColumn = ChangeMaxColumn;
StartOfSequence = i;
} else {
MinColumn = std::max(MinColumn, ChangeMinColumn);
MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
}
BreakBeforeNext = (i == 0) || (Changes[i].NewlinesBefore > 1) ||
// Never start a sequence with a comment at the beginning
// of the line.
(Changes[i].NewlinesBefore == 1 && StartOfSequence == i);
Newlines = 0;
}
alignTrailingComments(StartOfSequence, Changes.size(), MinColumn);
}
void WhitespaceManager::alignTrailingComments(unsigned Start, unsigned End,
unsigned Column) {
for (unsigned i = Start; i != End; ++i) {
int Shift = 0;
if (Changes[i].IsTrailingComment) {
Shift = Column - Changes[i].StartOfTokenColumn;
}
if (Changes[i].StartOfBlockComment) {
Shift = Changes[i].IndentationOffset +
Changes[i].StartOfBlockComment->StartOfTokenColumn -
Changes[i].StartOfTokenColumn;
}
assert(Shift >= 0);
Changes[i].Spaces += Shift;
if (i + 1 != Changes.size())
Changes[i + 1].PreviousEndOfTokenColumn += Shift;
Changes[i].StartOfTokenColumn += Shift;
}
}
void WhitespaceManager::alignEscapedNewlines() {
if (Style.AlignEscapedNewlines == FormatStyle::ENAS_DontAlign)
return;
bool AlignLeft = Style.AlignEscapedNewlines == FormatStyle::ENAS_Left;
unsigned MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
unsigned StartOfMacro = 0;
for (unsigned i = 1, e = Changes.size(); i < e; ++i) {
Change &C = Changes[i];
if (C.NewlinesBefore > 0) {
if (C.ContinuesPPDirective) {
MaxEndOfLine = std::max(C.PreviousEndOfTokenColumn + 2, MaxEndOfLine);
} else {
alignEscapedNewlines(StartOfMacro + 1, i, MaxEndOfLine);
MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
StartOfMacro = i;
}
}
}
alignEscapedNewlines(StartOfMacro + 1, Changes.size(), MaxEndOfLine);
}
void WhitespaceManager::alignEscapedNewlines(unsigned Start, unsigned End,
unsigned Column) {
for (unsigned i = Start; i < End; ++i) {
Change &C = Changes[i];
if (C.NewlinesBefore > 0) {
assert(C.ContinuesPPDirective);
if (C.PreviousEndOfTokenColumn + 1 > Column)
C.EscapedNewlineColumn = 0;
else
C.EscapedNewlineColumn = Column;
}
}
}
void WhitespaceManager::generateChanges() {
for (unsigned i = 0, e = Changes.size(); i != e; ++i) {
const Change &C = Changes[i];
if (i > 0) {
assert(Changes[i - 1].OriginalWhitespaceRange.getBegin() !=
C.OriginalWhitespaceRange.getBegin() &&
"Generating two replacements for the same location");
}
if (C.CreateReplacement) {
std::string ReplacementText = C.PreviousLinePostfix;
if (C.ContinuesPPDirective)
appendEscapedNewlineText(ReplacementText, C.NewlinesBefore,
C.PreviousEndOfTokenColumn,
C.EscapedNewlineColumn);
else
appendNewlineText(ReplacementText, C.NewlinesBefore);
appendIndentText(ReplacementText, C.Tok->IndentLevel,
std::max(0, C.Spaces),
C.StartOfTokenColumn - std::max(0, C.Spaces));
ReplacementText.append(C.CurrentLinePrefix);
storeReplacement(C.OriginalWhitespaceRange, ReplacementText);
}
}
}
void WhitespaceManager::storeReplacement(SourceRange Range, StringRef Text) {
unsigned WhitespaceLength = SourceMgr.getFileOffset(Range.getEnd()) -
SourceMgr.getFileOffset(Range.getBegin());
// Don't create a replacement, if it does not change anything.
if (StringRef(SourceMgr.getCharacterData(Range.getBegin()),
WhitespaceLength) == Text)
return;
auto Err = Replaces.add(tooling::Replacement(
SourceMgr, CharSourceRange::getCharRange(Range), Text));
// FIXME: better error handling. For now, just print an error message in the
// release version.
if (Err) {
llvm::errs() << llvm::toString(std::move(Err)) << "\n";
assert(false);
}
}
void WhitespaceManager::appendNewlineText(std::string &Text,
unsigned Newlines) {
for (unsigned i = 0; i < Newlines; ++i)
Text.append(UseCRLF ? "\r\n" : "\n");
}
void WhitespaceManager::appendEscapedNewlineText(
std::string &Text, unsigned Newlines, unsigned PreviousEndOfTokenColumn,
unsigned EscapedNewlineColumn) {
if (Newlines > 0) {
unsigned Spaces =
std::max<int>(1, EscapedNewlineColumn - PreviousEndOfTokenColumn - 1);
for (unsigned i = 0; i < Newlines; ++i) {
Text.append(Spaces, ' ');
Text.append(UseCRLF ? "\\\r\n" : "\\\n");
Spaces = std::max<int>(0, EscapedNewlineColumn - 1);
}
}
}
void WhitespaceManager::appendIndentText(std::string &Text,
unsigned IndentLevel, unsigned Spaces,
unsigned WhitespaceStartColumn) {
switch (Style.UseTab) {
case FormatStyle::UT_Never:
Text.append(Spaces, ' ');
break;
case FormatStyle::UT_Always: {
unsigned FirstTabWidth =
Style.TabWidth - WhitespaceStartColumn % Style.TabWidth;
// Insert only spaces when we want to end up before the next tab.
if (Spaces < FirstTabWidth || Spaces == 1) {
Text.append(Spaces, ' ');
break;
}
// Align to the next tab.
Spaces -= FirstTabWidth;
Text.append("\t");
Text.append(Spaces / Style.TabWidth, '\t');
Text.append(Spaces % Style.TabWidth, ' ');
break;
}
case FormatStyle::UT_ForIndentation:
if (WhitespaceStartColumn == 0) {
unsigned Indentation = IndentLevel * Style.IndentWidth;
// This happens, e.g. when a line in a block comment is indented less than
// the first one.
if (Indentation > Spaces)
Indentation = Spaces;
unsigned Tabs = Indentation / Style.TabWidth;
Text.append(Tabs, '\t');
Spaces -= Tabs * Style.TabWidth;
}
Text.append(Spaces, ' ');
break;
case FormatStyle::UT_ForContinuationAndIndentation:
if (WhitespaceStartColumn == 0) {
unsigned Tabs = Spaces / Style.TabWidth;
Text.append(Tabs, '\t');
Spaces -= Tabs * Style.TabWidth;
}
Text.append(Spaces, ' ');
break;
}
}
} // namespace format
} // namespace clang